1. Field of the Invention
The present invention relates to a capsule type endoscope having a capsule body internally equipped with an image taking device for taking images in the body cavity of a human subject.
2. Description of the Related Art
An endoscope can be inserted into the esophageal canal of the human subject to directly examine the inner wall of any affected region of interest with high reliability. However, this method needs relatively large equipment and, in addition, a large burden is inflicted on the patient and operator. Therefore, such conventional endoscopy is hard to adopt in a first screening such as mass screening.
As a first screening such as mass screening, in general, it is usually only necessary to examine the presence or absence of any affected region of interest at least, and a simpler examination should be adopted from the standpoint of reduced cost, pain and psychological unrest.
Therefore, it has been desired to establish simpler checking means for adopting a first screening program by which it is possible to directly and exactly check the esophageal wall for any affected new region of interest.
One approach is directed to a camera type of system according to which an endoscope is formed as a capsule configuration and, by swallowing such a capsule, images are taken by that camera-incorporated capsule during its passage through the esophageal canal to allow the corresponding image signals to be, for example, wirelessly transmitted to the outside in realtime.
However, upon image transmission in realtime, the video frame rate is normally very slow at two frames per second, while, on the other hand, the time during which the capsule passes through the esophageal canal is very short, being of the order of one second. As a result, only about one or two frames can be obtained during the passage of the capsule through the esophageal canal. Therefore, adequate reliability can not be ensured at such a frame rate and hence it is not suitable for the examination of the esophagus. Further, there has been some inconvenience in that exact examination of not only the esophagus but also the internal organs such as the stomach, the duodenum the small intestine and the large intestine can not be made for any affected region of interest or its neighborhood.